1. Field of the Invention
This invention generally relates to an electronic musical instrument, and more particularly, to a device (hereunder sometimes referred to simply as an accompaniment detecting device) for detecting the contents of an accompaniment (for example, a chord accompaniment or a bass accompaniment) for use in an electronic musical instrument.
2. Description of the Related Art
Accompaniment detecting devices are now widely used in automatic instruments and the like. Conventional automatic instruments and the like, and most of the many conventional automatic instruments now manufactured automatically play chords by using a part of the keys of a keyboard thereof corresponding to a succession of the lowest pitches as a portion (hereunder referred to as a chord detecting portion) of keys for detecting chords, by also using the other portions of the keys of the keyboard as a portion of the keys for playing melodies, and by detecting which keys of the chord detecting portion are pressed. Further, such conventional automatic instruments are adapted to automatically play a chord with an automatic rhythm accompaniment, obtained by simply continuing to press keys corresponding to pitches composing the chord.
The accompaniment detecting devices of the conventional automatic instruments, however, have problems in that it is difficult to designate a bass accompaniment independently of a chord accompaniment and that it is hard to discriminate among a root-position chord and its inversions which of the lowest-sounding pitches are different from the root of the root-position chord. The present invention is created to resolve the above described problems of the conventional accompaniment detecting devices.
Accordingly, an object of the present invention is to provide an accompaniment detecting device which can easily designate a bass accompaniment independent of a chord accompaniment, and accurately detect a chord and its inversion.